The Oregon Supreme Court has succeeded in doing what scores of public meetings, thousands of pages of reports, and endless public relations spin could not: Give us the original rationale behind the proposed $3.5 billion Columbia River Crossing.

The answer, according to the court: The massive Interstate 5 bridge and freeway project is a "political necessity" to persuade Clark County residents to accept something they previously didn't want—a MAX light-rail line from Portland to Vancouver. (To read the Feb. 16, 2012 Oregon Supreme Court decision regarding the Columbia River Crossing Project, click here(PDF, 18 pages))

Project opponents filed a legal challenge to the way Metro, the regional planning agency, granted sweeping land-use approval to the project. The Oregon Supreme Court sided mostly with Metro.

But Chief Justice Paul De Muniz, writing for the majority, highlighted an inconvenient set of facts for CRC backers.

He wrote in the Feb. 16 opinion that most of the project—namely the 10-lane freeway bridge and new interchanges—was put forward to get Clark County to agree to the light-rail line.

De Muniz cited statements that Metro made in the land-use process and Metro's lawyer repeated before his court.

"It was politically impossible for the light rail project to proceed without also building new interstate bridges across the Columbia River,â De Muniz wrote.

"Or as Metro later summarized it: 'There is no light rail without the freeway bridge[s] being replaced.'"

Backers have cited traffic and safety issues as the top reasons to build the CRC. But the court ruling means those and other justifications were created after officials decided to give a sop to Clark County, now worth $2.5 billion.

Metro had used a law originally intended to site light-rail lines to justify the project. (Only 27 percent of the project's cost—or about $950 million—will go to building the light-rail portion of the CRC.) Metro won every legal challenge, including at the state Supreme Court.

De Muniz highlighted Metro's land-use decision. In it, the regional agency explains the freeway bridge and associated improvements were necessary to get the light-rail line built after Clark County voters in 1995 overwhelmingly rejected funding for a new light-rail line.

Supporters of the bridge project acknowledged the new freeway bridge and $1 billion in interchanges were necessary to sway Clark County to go for the deal.

"To get light rail built, we need to have some highway improvements associated with it," Mark Greenfield, an attorney for Metro and TriMet, told the Supreme Court in December.

Mike Lilly, a lawyer for Plaid Pantry, a losing petitioner in the Supreme Court case, says the ruling exposes an expensive truth about the CRC.

"We are stuck paying for a huge highway bridge and interchanges as an inducement to get Vancouver to accept light rail,â he says.

CRC spokeswoman Anne Pressentin says the courts have established that Metro followed the law properly when it granted the CRC's land-use approvals.

Pressentin also says how the new freeway bridge and interchanges got on the drawing board in the first place no longer matters—the CRC project has proven the region needs both the freeway improvements and light rail.

"There are a lot of things that happened along the way," she says. "There's no inconsistency here."